The invention relates to a multi-directional arch expanding device which comprises a plastic base plate coincident with a cavity of the palate of a patient, spiral opening devices, first
premolar metal retention union crowns on the left side / right side, second
premolar metal retention union crowns on the left side / right side, first
molar metal retention single crowns on the left side / right side and
arch wires. The plastic base plate is divided into
premolar area base plate bodies on the left side / right side and
molar area base plate bodies on the left side / right side, the premolar area base plate body on the left side is connected with the
molar area base plate body on the left side through the spiral opening devices, the premolar area base plate body on the right side is connected with the molar area base plate body on the right side through the spiral opening devices, the premolar area base plate body on the left side is connected with the premolar area base plate body on the right side through the spiral opening devices, and the
arch wires are placed in MBT brackets of the first premolar metal retention union crowns on the left side / right side and the second premolar metal retention union crowns on the left side / right side and MBT
cheek tubes of the first molar metal retention single crowns. The multi-directional arch expanding device has the advantages that bony structures of all teeth and the anterior palate part before the premolars on the two sides provide a strong support for distal movement of premolars; the metal crowns
well control the vertical directions and the horizontal directions of the back teeth, tooth extending, lowering or twisting possibly occurring in distal movement is avoided.